Add connector for sub-api

[vikiival]

Tasks:

• [x] make route /settings
• [ ] make input that should take url and will connect to the node
• [ ] make store for that ? (maybe also check some sort of persistence?)

[dudo50]

To explain this issue further, The current stage of Paraspell UI is that you can start the localhost network via docker config and then log in to endpoints that are predefined and use them in UI (Without any modification needed). This can however be a little limiting for developers who might want to connect to some other endpoints, maybe on testnet or main net.. (Through "wss endpoints").. We need config, a simple config, that will allow through /settings to connect to the custom node endpoint via "wss or ws" and allow for transferring to other Parachains.. These endpoints given by the user can be then stored in the store. There should be some by default (Those from localhost network, can be found in paraspell/ui and network config + one ending with 9944 (Relay chain))

(Screen should look something like this) - just more styled

[dudo50]

@Roman-24 any news on this?

[vikiival]

cc @dudo50

Ref #40